<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>css</title>
    <style>
        .list li{
            list-style: none;
            width: 150px;
            height: 32px;
            line-height: 32px;
            text-align: center;
            font-size: 14px;
            margin: 8px;
            border: 1px solid rgb(0, 0, 0);
        }
        .gb{
            color: #0f0;
            font-weight: bold; 
        }
        .list .xu{
            border: 1px dotted #000;
        }
    </style>
</head>
<body>
    <ul class="list">
        <li>标签选择器</li>
        <li>ID选择器</li>
        <li class="gb">class类选择器</li>
        <li>父子选择器</li>
        <li class="gb">伪类</li>
        <li class="xu">群组选择器</li>
        <li class="gb xu">交集选择器</li>
    </ul>
</body>
</html>